Barrier submersion cooking pouch and basket

ABSTRACT

A system and method for barrier submersion cooking comprising a thin walled plastic cooking pouch for receiving a food item effectively dimensioned such that when placed into a hot liquid cooking medium a vent remains above a top surface of the liquid cooking medium and a rack for lowering the vessel into the liquid cooking medium to an effective depth such that the food item received by the pouch is below the top surface of the liquid cooking medium and the vent is above the top surface of the liquid cooking medium. The pouch is formed of food grade pliable polymer film having a melt temperature above that of a temperature used in conventional hot oil flying processes, a heat transfer rate of an effective value to substantially instantaneously transfer heat from the liquid cooking medium to create an effective frying temperature upon the food item, and a pliability such that the pouch will collapse on itself when exposed to hydrostatic pressures when submerged within the liquid cooking medium, thereby effectively transferring heat to all food item surfaces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation Application which claims the benefit of U.S.patent application Ser. No. 11/830,957, filed, Jul. 31, 2007, whichclaims the benefit of U.S. provisional application Ser. No. 60/821,062filed Aug. 1, 2006 and U.S. provisional application Ser. No. 60/884,897,filed Jan. 15, 2007, and is a continuation-in-part of and claims thebenefit of U.S. application Ser. No. 10/709,273 filed Apr. 26, 2004, allincorporated by reference herein.

FIELD OF THE INVENTION

This invention relates generally to the preparation of food and inparticular, to an improved apparatus and method for barrier submersioncooking.

BACKGROUND OF THE INVENTION

Deep fryers are one of the most useful and popular devices in thecommercial kitchen. Deep fryers have been used for years to make frenchfries, breaded foods, and specialty pastries. Their highly efficient anduniform heat transfer rate results in fast, accurate, and economicalcooking.

The modern deep fryer consists of a large well or heating chamber whichis filled with cooking oil. The cooking oil is heated to between 350degrees to 400 degrees F. by electric resistance heaters inside the wellor gas fired burners located below the heating chamber. Food items to becooked are placed in wire baskets and lowered into the hot oil to apoint of total submersion. Due to the high efficiency of liquid-to-solidheat transfer as well as the high ratio of hot oil volume to cool foodvolume, heat is rapidly transferred from the hot oil into the cool foodproduct. This rapid and even heat transfer tends to produce a crispouter surface while heating the foods inner core. The crisp outer foodsurface acts to seal the food while the moisture on the interior of thefood is rapidly increased in temperature effectively steaming the insideof the food. This results in cooked foods such as french fries, friedchicken, or donuts which are crisp on the outside and moist and hot onthe inside.

The flavor and unique texture of deep fried foods are key to theirpopularity. Inherent in this cooking method is a tendency for the fooditems to absorb a percentage of the oil in which they are being cooked.The amount of oil absorbed into the food can be somewhat reduced byadjusting the oil type and temperature, however, even under the bestcircumstance, some oil is absorbed into the food. This absorbed oilsubstantially increases the fat content of the food. High fat content isundesirable in foods. As a result, fried foods are linked to obesity andother health problems.

To eliminate the oil absorption problem, various methods of air fryinghave been created. Air frying consists of a stream of hot air into whichthe food product is introduced. The heat transfer efficiency ofair-to-solids is lower than the heat transfer efficiency ofliquid-to-solids. In an effort to improve heat transfer, a thin coat ofoil is typically added to the surface of the food before heating. Theoil acts as a heat transfer medium more efficiently coupling the hot airto the cooler food product.

The hot dry air which is used to satisfactorily heat the food causesmoisture to evaporate from the food product. Air fried foods typicallyhave a dry outer surface which is less crisp than deep fried foods.Moisture also tends to evaporate from the core of the food as thesurface is heated. As a result, due to its poor texture and lessdesirable taste, air fried foods have not found the level of acceptancetypical of deep fried food. New food products have been developed in aneffort to overcome the deficiencies of air frying but none has equaledthe acceptance of deep fried foods.

In an effort to gain the advantages of liquid-to-solid heat transferwhile avoiding the disadvantages of food absorption of the liquid,various submersion barrier cooking techniques have been developed.Submersion barrier cooking requires the food item be held in acontainer, the container thereafter being submerged into the heatedliquid. In theory, the container is fabricated of a material whose heattransfer rate is sufficiently efficient to not appreciably degrade thetransfer of heat from the heated liquid to the food. However, inpractice, prior attempts at submersion barrier cooking have failed toproduce a cooked food product which equals the taste and texture of thatproduced by traditional deep frying.

Accordingly, there remains a continuing need for improved methods toisolate a food product from the cooking liquid yet continue to maintainthe flavor and texture of that produced by traditional deep frying. Thepresent invention fulfills this need, and further provides relatedadvantages.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to an improved pouch and basket designused in barrier submersion cooking of food items using standard deepfryers. The present invention places the food item into a disposablehigh temperature thin film plastic cooking pouch fabricated from amaterial with an effective heat transfer rate that will cause thetemperature of the interior vessel wall to achieve effective fryingtemperature substantially instantaneously after placement into hotcooking oil.

The disposable plastic cooking pouch of the present invention hasimportant advantages over reusable cooking vessels and cooking pouchesfabricated from metal. Reusable vessels are rigid and do not conform tothe shape of many food items. The metal vessels have greater weight andconduct more of the heat away from the food than do the disposablepouches of the present invention. Additionally, reusable vessels must becleaned after use.

Disposable cooking pouches fabricated from aluminum and other metalfoils exhibit a tendency to leak from weakness around the seams and morenotably from stress risers, which are created as the foil is manuallycompressed to form tightly around the contours of the food item prior toplacement within the cooking oil. Also, air pockets between the fooditem and foil are formed due to the foil's relatively rigid nature andthe food item's many contours. Foil gauge and seam design have littleimpact in improving the metal pouch's tendency to develop leaks. Thethin walled plastic cooking pouch of the present invention whichcollapses upon itself when exposed to cooking oil hydrostatic pressuresobviates these problems.

Loading food items into a thin walled cooking pouch can be bothdifficult and time consuming. The cooking pouch's thin material makes itparticularly difficult to both find the pouch's top opening and to graspand pull apart the sides of the pouch. The novel food slide of thepresent invention provides an improved method for easily and efficientlyloading a thin walled pouch.

A typical loaded cooking pouch floats in the hot oil used in the barriersubmersion cooking process. As the pouch floats, it tends to move out ofthe confines of known wire baskets through the basket's side loadingentrance. Once freed from the confines of the wire basket, the food'sbuoyancy allows the pouch to rise to the surface of the cooking oilcausing the cooking pouch to capsize, thereby allowing hot oil to enterthe pouch through its top vent and contaminate the food item inside. Thenovel slant wire basket design of the present invention prevents suchpouch migration.

In a preferred embodiment, a thin walled plastic pouch having an opentop is effectively dimensioned to receive a food item and thereafter beplaced into the hot oil of a deep fryer while maintaining a vent abovethe top surface of the oil. The pouch open top serves as the vent.

Using a slant wire rack, the pouch is lowered into the deep fryer's hotoil to an effective depth such that the food item is below the surfaceof the oil while the vent remains above the top level of the hot oil,preventing the oil from entering into the pouch and directly contactingthe food item. Oil hydrostatic pressure operating against the thin wallplastic pouch causes it to collapse around and intimately contact thefood item as it is immersed within the oil. Due to the high heattransfer characteristics inherent in the pouch material, heat issubstantially instantaneously transferred from the hot oil through thecooking pouch to the food item contained within.

The food item, which is in intimate contact with the pouch, startsfrying nearly immediately. Steam and hot vapors omitted from the foodduring the frying process vent through the top opening of the pouch.

Another advantage of the submersion barrier cooking process of thepresent invention is that the thin walled plastic cooking pouch does nothave to be preheated because it is substantially instantly brought up tocooking temperature when submerged into the hot cooking oil.

Yet another advantage of the present invention is that a food item willbe more evenly heated over its entire surface than that achieved bynon-deep fried methods while avoiding absorption of unhealthy cookingoil inherent in traditional deep fried cooking.

Still another advantage is the cost savings achieved in the commercialenvironment, in that no additional special cooking equipment is requiredother than a restaurant's existing deep fryer and the pouch and rack ofthe present invention. The present invention allows a restaurant toextend its cooking capabilities without additional significant equipmentpurchases.

Other features and advantages of the present invention will be apparentfrom the following more detailed description of the preferredembodiments, taken in conjunction with the accompanying drawings whichillustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an end view of the pouch containing basket inserted intocooking oil.

FIGS. 2 and 3 are perspective views of a first pouch form.

FIGS. 4 through 9 are perspective views of the formation of a secondpouch form.

FIGS. 10 through 12 are perspective views of the formation of a thirdpouch form.

FIGS. 13 and 14 are perspective views of the food slide delivering afood item to the pouch.

FIG. 15 is a top view of the rack.

FIG. 16 is an end view of the rack.

FIG. 17 is a side view of the rack.

FIG. 18 is a perspective view of the rack.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to FIG. 1, thin walled plastic cooking pouch 2 is formed offood grade pliable polymer film having a melt temperature above that oftemperatures used in conventional hot oil frying processes, generallyabout 350 degrees to about 400 degrees F.; a heat transfer rate of aneffective value to substantially instantaneously transfer the heat fromhot cooking oil 12 to create effective frying temperature at food item10; and a pliability such that it will collapse on itself when exposedto oil hydrostatic pressures when submerged within the oil 12. Such foodgrade polymers include, for example, polyamide film such as nylon 66 andpolyester film such as mylar.

Pouch 2 is sealed on three sides while maintaining a patent open top 30(FIGS. 2 and 9). Pouch open top 30 must have a patent opening so thathot steam and other vapors created by rapidly cooking food item 10 canvent while at the same time maintaining intimate contact with food item10. Pouch open top 30 may optionally be sealed using, for example, aninterrupted seal, or alternatively, a vapor permeable seal, or apressure release seal. Such seals while permitting vapors to vent, havethe additional advantage of maintaining food item 10 integrity duringtransit.

For purposes of this disclosure, thin walled is meant to include a pouchwall thickness such that pouch 2 will collapse around and intimatelycontact food item 10 contained within pouch 2 when exposed to hotcooking oil 12 hydrostatic pressures.

In a preferred embodiment, pouch 2 is formed from, for example, mylarfilm having a film thickness of about 0.001 inch. The pliable nature ofthe plastic film allows hydrostatic pressure from cooking oil 12 topress the film tightly against the convoluted surfaces of food item 10contained within pouch 2. The close coupling of pouch 2 to the surfaceof food item 10 eliminates cool air pockets inside pouch 2, resulting inmore evenly cooked food.

Turning to FIGS. 2 and 3, in a first pouch form, film 14 is folded onitself so as to create an opening 4, optionally, an offset, hemmedopening. Sides 6 are sealed, for example, by conventional heating orultrasonic seaming methods, creating seam 16.

In a second pouch form, shown in FIGS. 4 through 9, conventional hightemperature coated cooking film 18 is used. Such known films have anuncoated side 8 and a coated side 20 that can be heat sealed to itselfat temperatures below the melting temperature of film 18. Film 18 isfolded on itself and hemmed such that coated hemmed areas 22 face theinside of pouch 2. Hemmed film 24 is folded in half whereupon heat andpressure are applied to hemmed areas in conventional manner to form seal26. Thus, film coated side 20 is maintained on the outside of pouch 2 sothat the pouch insides do not adhere to each other once collapsed uponpouch 2 placement in hot oil 12.

In a third pouch form, shown in FIGS. 10 through 12, a pattern coat offood grade high temperature adhesive is applied to a predetermined areaof film 18, for example, the edges 90 of film 18. Film 18 is thereafterfolded in half such that the edges adhere to one another, forming pouchseal 26. It should be apparent that any pattern application that resultsin pouch formation is contemplated by the invention.

Food item 10 is inserted into pouch 2 prior to pouch 2 immersion. Forease of placement, optionally, food slide 28 is utilized, shown in FIGS.13 and 14. Food slide 28 is dimensioned such that it can be insertedinto pouch open top 30. Once inserted to contact the bottom of pouch 2,food item 10 is slid down food slide 28 and food slide 28 is thereafterwithdrawn. In this manner food item 10 remains properly positioned atthe bottom of pouch 2.

Turning to FIGS. 1 and 15 through 18, prior to submersion, pouch 2 isinserted into and supported by rack 40. Rack 40 may hold a single pouch2 or a plurality of pouches 2, thereby permitting simultaneous cookingof multiple food items 10. The number of pouches 2 is limited only byrack 40 design. Rack 40 is utilized to insure effective positioning ofpouch 2 in hot cooking oil 12. Rack 40 supports pouch 2 in asubstantially vertical position, thereby maintaining pouch open top 30above the surface of hot cooking oil 12.

Rack 40 and pouch 2 are lowered into hot liquid, for example, hotcooking oil 12 contained by a deep fryer (not shown) to a sufficientdepth such that pouch 2 and, hence, food item 10 are below top surface42 of hot cooking oil 12 to a depth sufficient to allow effective heattransfer from hot cooking oil 12 through pouch 2 to food item 10 tofully cook food item 10. Hot cooking oil 12 substantiallyinstantaneously raises the temperature of pouch 2 to an effective fryingtemperature. Pouch top opening 30 serves as a vent and remains above hotcooking oil top surface 42 an effective distance to prevent hot cookingoil 12 from coming into direct contact with food item 10.

Due to the excellent heat transfer characteristics inherent in film 18,heat is substantially instantaneously transferred from hot cooking oil12 through pouch 2 to effectively fry food item 10 held within. Cookingoil 12 hydrostatic pressure collapses pouch 2 placing it in intimatecontact with substantially all surfaces of food item 10, causing fooditem 10 to effectively immediately start frying. Steam and hot vapors(not shown), which may be omitted from food item 10 during the fryingprocess, escape through pouch top opening 30, which serves as a vent.

Rack 40 is fabricated from, for example, wire frame 54. Pouch supportsection 56 is attached at a first end to handle 58 and at a second endto hanger 60. Hanger 60 rises superior to support section 56 such thatwhen engaged with a deep fryer hanger rail (not shown), pouch 2 issubmerged in hot cooking oil 12 and handle 58 is not. Hanger 60 is alsoused to support rack 40 when rack 40 is suspended above hot cooking oil12 to permit drainage of hot cooking oil 12.

Pouch support section 56 comprises superior longitudinal members 66separated by superior cross members 64. Superior cross members 64support handle 58 and hanger 60. Vertical member 68 is attached tosuperior cross member 64 and lower cross member 70. At least one lowercross member 70 separates inferior longitudinal members 72. Inferiorlongitudinal members 72 are dimensioned such that pouch 2 rests upon andis supported by at least one inferior longitudinal member 72.

Slanted cross member 74 is attached to rear vertical member 76 superiorto its attachment to front vertical member 78. Rear vertical member 76is positioned and dimensioned to restrict pouch 2 from exiting the rearof basket 40. Pouch 2 is inserted into basket 40 through basket openside 80. In this manner, as pouch 2 floats upon immersion in cooking oil12, slanted cross member 74 causes pouch 2 to float towards the rear ofbasked 40, where it is prevented from exiting basket 40 by rear verticalmember 76. Slanted cross member 74 is positioned and dimensioned toprevent pouch 2 from exiting basket 2 through its top.

Although the present invention has been described in connection withspecific examples and embodiments, those skilled in the art willrecognize that the present invention is capable of other variations andmodifications within its scope. These examples and embodiments areintended as typical of, rather than in any way limiting on, the scope ofthe present invention as presented in the appended claims.

1. A system for barrier submersion cooking comprising: a. a thin walledcooking pouch for receiving a food item, said cooking pouch including avent and dimensioned such that when lowered into a hot liquid cookingmedium said vent remains above a top surface of the liquid cookingmedium; b. a rack for lowering said pouch into the liquid cooking mediumto a sufficient depth such that the entire food item received withinsaid pouch is submerged below the top surface of the liquid cookingmedium and said vent is above the top surface of the liquid cookingmedium, wherein said rack comprises a body having an open side, saidbody being dimensioned such that said pouch can enter and exit onlythrough said open side, and wherein said body is dimensioned such that afloating pouch is directed away from said open side and is preventedfrom exiting said rack, wherein said body further comprises a slantedcross member attached within said body effectively dimensioned andlocated to direct a floating pouch away from said open side; c. saidpouch, upon being exposed to hydrostatic pressures from the liquidcooking medium, collapsing upon the food item contained therein suchthat said pouch intimately contacts substantially the entire surface ofthe food item contained therein; and, d. wherein said pouch is formed ofliquid impermeable food grade pliable film having a melt temperatureabove that of a temperature used in conventional hot oil fryingprocesses.
 2. A cooking rack for barrier submersion cooking, saidcooking rack comprising: a. a body having a top and an open side forreceiving a pouch, said body constructed to include no moving parts; b.a bottom support member for supporting the pouch, and a rear side, thebody dimensioned such that the pouch can only enter and exit through theopen side, said body dimensioned such that a floating pouch is directedaway from the open side; c. a handle attached to the body for carryingthe rack; d. a hanger attached to the body positioned for suspending therack when hung on a rack hanger; and, e. wherein said rack is arrangedfor holding a plurality of said pouches to permit simultaneous cookingof multiple food items contained within said plurality of said pouches,said cooking rack further comprising a slanted cross member attachedwithin said body effectively dimensioned and located to direct afloating pouch away from said open side.